The U.N. humanitarian chief has criticized all parties to the Yemen conflict for attacks against civilians.

The “most pressing concern” there now is the protection of civilians, Stephen O’Brien told the Security Council Thursday.

“Protected places such as hospitals, schools and homes continue to be hit by all parties,” he said via a video link from Brussels. “It is unacceptable that health facilities are being hit, and it is critical that the parties make guarantees that these locations will be protected,” he said.

O’Brien said since the start of the war nearly one year ago, some 2,000 children have been injured or killed -- including at least 90 killed this year -- from airstrikes, shelling, ground fighting and unexploded artillery.

He emphasized that all parties are obligated under international humanitarian law to take steps to protect civilians and places they inhabit.

Humanitarian Crisis

The conflict between the Saudi-backed government and Iranian-supported Shi’ite Houthi rebels has killed more than 6,000 Yemenis and injured over 35,000 others. More than two million people have been displaced by the fighting.

The U.N. and its partners estimate that 21.2 million people -- 82 percent of the population – require some form of humanitarian or protection assistance.

FILE - Yemenis carry relief supplies as they walk along a path outside the city of Taiz, Yemen, Jan. 17, 2016.

Last week, the United Nations appealed for $1.8 billion to meet Yemen’s humanitarian needs this year.

O’Brien blamed a “proliferation of checkpoints” across Yemen, as well as bureaucratic requirements imposed by the Houthi rebels for delaying aid deliveries. He did welcome Wednesday’s release of a World Food Program ship which had been diverted by the Saudi coalition last month to a Saudi port. O’Brien said the food and medical aid on-board had been delivered as planned to Hudaydah, and some communications equipment for aid workers would arrive in Aden on Sunday.

Peace Talks

The U.N. envoy on Yemen, Ismail Ould Cheikh Ahmed, said last month that “deep divisions” among the parties had prevented him from restarting stalled peace talks, and he urged a recommitment to a cessation of hostilities. He said he hoped to restart talks in March, but so far no date has been announced.

“The time is against us. The situation is catastrophic. The political solution is becoming more than ever needed today, and we need to precipitate these talks as soon as possible,” he told reporters on February 17.